Abstract: A control device for a matrix printer in which the mechanical printing elements of the matrix printer are selectively triggered by the control device a certain time before they reach the desired printing spot on the information carrier in order to compensate for the fact that the printing head will move further over a certain distance between the triggering moment and the moment that the printing element actually hits the information carrier. This distance depends on the speed of the printing element. If the print signal, however, is always generated a constant distance before the printing element reaches the desired printing spot, this signal must be delayed as a function of the speed of the printing element if the printing head is to print accurately also during its run-up and slow-down. To this end, a delay device is provided which delays the print signal for the relevant printing element by a time interval which depends on the printing head speed.

Abstract: In matrix printers, the printing elements in the printing head are frequently arranged so that they do not correspond to the printing raster of the characters to be printed so that the informations delivered for each time a printing column at the same time must be delayed a time. For this purpose, a delay device is assigned to each printing element of a matrix printer, the delay times for each device representing paths mutually depending upon the orientation and spacing of the printing elements in the printing head and being determined by the time interval between a common writing pulse and individual element read-out pulses, which are produced by a shift register, in which the writing pulse is shifted at a relatively high rate depending upon the head position, the read-out pulses for the elements being produced by tappings on the shift register.

Abstract: An office machine, for example, a printer, with a printing unit, individual paper transport via driving rollers and endless paper transport via a tractor is to be designed in such a way that as many operating modes as possible can be obtained by simple means. This is achieved at least one releasable cassette for individual paper is in the entry region of a printing unit. A tractor is pivotalby adjustable into a pushing and a pulling position and is located behind the printing unit. The following operating modes are selectable by adjustment of the tractor positions coupled to further components:a. Straight individual paper transport from the front via driving rollers either by manual infeed or by automatic cassette infeed, the tractor being in the pushing position.b. Curved endless paper transport from the rear via the tractor set in the pushing position and via a portion of the driving rollers.c. Straight endless paper transport from the front via the tractor set in the pulling position.

Abstract: An arrangement for indicating the refilling level of a collapsible ink container (1,2) comprising a measuring circuit having an alternating voltage source (U.about.) to form an electric control signal which depends on the capacitance (8) between the liquid ink and an electrically conductive coating (5) which is insulated with respect to the ink by the wall of the ink container wherein the electrically conductive coating (5) is provided on the outside of the lower part (1) of the ink container.